Synthesis, Analytical, and Spectral Studies on Manganese (II) complexes of Redox-active Schiff base Ligands, Bis (2,5-dihydroxyacetophenone) ethylenediamine and Bis (2,5-dihydroxyacetophenone) propylenediamine

This study explores the synthesis, analytical characterization, and spectral properties of manganese (II) complexes derived from redox-active Schiff base ligands, specifically bis(2,5-dihydroxyacetophenone) ethylenediamine (DAen) and bis(2,5-dihydroxyacetophenone) propylenediamine (DApn). These ligands were synthesized by condensing 2,5-dihydroxyacetophenone with ethylenediamine and 1,3-propylenediamine, respectively. The resulting manganese (II) complexes were prepared through reactions with Mn(II) salts under controlled conditions. Comprehensive analytical techniques, including elemental analysis, and magnetic susceptibility measurements, confirmed the successful synthesis and composition of the complexes. Spectral studies using UV-Vis, IR, and EPR spectroscopy provided detailed insights into the electronic structures and binding modes of bivalent mononuclear manganese(II) centres in these metal complexes. The results revealed that the Schiff base ligands coordinate with manganese (II) ions through the phenolic oxygen and imine nitrogen atoms, forming stable, near octahedral geometries. This work contributes to understanding manganese (II) coordination chemistry with Schiff bases and underscores their potential in materials science and catalysis.